First a couple of previous forays re physical constants:

Stephen Baxter's "Raft" boosts "G".

Neal Stephenson's "Anathem" turns on subtle variations in physical constants.

It might be interesting to play with compressibility of materials. Wil McCarthy's "Queendom of Sol" series features hyperdense material used to give asteroids ("planettes") respectable surface gravity.

I'm reminded of Bob Shaw's "Orbitsville", where a Dyson sphere is a honey trap whose attraction is that there's too much living space to quarrel over -- not a change of physical constants, but physical constraints.

I'd be intrigued by a slightly more sensitive mirror neuron system. The opposite -- low empathy -- is a theme of Neal Barrett Jr's "Stress Pattern".